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It is well known that dielectrics with the reconstruction of zone structure (Pb1-xSnxTe, for example) have two-dimensional layers with a specific electron properties. A corresponding relativistic model has been discussed, in particular, by B.A. Volkov and O.A. Pankratov (1985). The general nature of the effect under consideration can be demonstrated by in a simple model setting, and the aim here i

We report experimental studies of harmonic generation in Xe using a 1064 nm Nd-YAG laser. Third-harmonic conversion is observed in a positively dispersive medium, using a tight-focusing geometry. The intensity of third-harmonic generation in a gas cell varies much more steeply with the laser intensity than a cubic law. The reason for the breaking of the phase matching condition is discussed.

Novel short-pulse X-ray sources, e.g., laser-produced plasmas, offer new approaches to the solution of the scatter-reduction problem in X-ray imaging, by the use of time-gated detection techniques. Monte Carlo simulations are used to estimate the scatter-reduction performance of time-gated imaging techniques within a range of X-ray energies, gating times and tissue parameters, Significant improvem

Inspired by the experimental work performed in the research group led by Ville Maisi at Lund University, this thesis investigates a hybrid quantum setup in circuit quantum electrodynamics (cQED). The system consists of a microwave resonator coupled to a double quantum dot (DQD) acting as an internal sensor to indirectly detect the state of an external quantum system. Using input-output theory and

The suppression of chaos in quantum reality is evident in quantum scars, i.e. in enhanced probability densities along classical periodic orbits. They provide opportunities in controlling quantum transport in nanoscale quantum systems. Here, we study energy level statistics of perturbed two-dimensional quantum systems exhibiting recently discovered, strong perturbation-induced quantum scarring. In

Quantum measurement theory has a peculiar nature with its TWO processes of assertibility, by proof and by measurement, which is beyond formal logic. This two-sortedness with respect to assertibility is discussed in terms of developments of many--sorted logics, sometimes referred to as Logica Magna. Although useful insights are obtained this way, we argue that there is a nonseparability of inferrib

Quantum dot based parity-to-charge conversion is a promising method for reading out quantum information encoded nonlocally into pairs of Majorana zero modes. To obtain a sizable parity-to-charge visibility, it is crucial to tune the relative phase of the tunnel couplings between the dot and the Majorana modes appropriately. However, in the presence of multiple quasidegenerate dot orbitals, it is i

Popular Abstract in Undetermined All of our present information technology culture with computers, internet, smart-phones, Bluetooth links, 3D-Tv, iPad tablets, programmable washing/cooking machines, car engines, navigation computers, etc. (the list goes on and on) is based on small electrical circuits. The smaller these circuits can be made, the faster and the better microelectronics can perform.

Many emergent phases of matter stem from the intertwined dynamics of quasiparticles. Here we show that a topological superconducting phase emerges as the result of interactions between electrons and magnons in a quantum wire and a helical magnet. The magnon-mediated interaction favors triplet superconductivity over a large magnetic phase space region, and stabilizes topological superconductivity o

We show that polarized few-electron concentric double quantum rings display localized states that are the quantum analog of classical equilibrium ones. These states have very similar energies but fairly different angular momenta, constituting a new physical realization of the isomeric states found in nuclear and molecular physics. Their fingerprint is a very soft mode in the infrared-absorption sp

The 30 articles in this special section cover a broad range among the following areas: advanced bioimaging; multifunctional endoscopy; novel approaches in biophotonic diagnostics and therapeutics; advanced biophotonic sensing techniques; laser-cell interactions; photoacoustics and terahertz biophotonics; nanobiophotonics; and novel laser, fiber-optics and electrooptics biophotonic tools, and devic

A theory of self-induced transparency for a TM-mode propagating in a planar semiconductor waveguide sandwiched between two dielectric media is developed. A transition layer between the waveguide and one of the connected media is described using a model of a two-dimensional sheet of quantum dots. Explicit analytical expressions for the optical soliton in the presence of single-excitonic and biexcit

Entanglement production is one of the properties of interest when studying nanoscale systems. Not only does entanglement between subsystems hints at other non-classical behaviour and effects that may be of interest to applications; the resource of entangled systems themselves is one on which many future devices and protocols may depend on. In this thesis work, a system of two quantum dots coupled

Quantum metrology is a rapidly growing field of quantum information science that aims to exploit the counter-intuitive properties of quantum systems to estimate physical quantities with better-than-classical precision. The field primarily deals with the problem of estimating system parameters, which may or may not directly be associated to an observable. A prominent result of quantum metrology is

Nanowire quantum dots have shown promise as energy filters in thermoelectric applications. However, anomalous effects in the thermocurrent have been observed when heat is applied in close proximity to the quantum dot. This work began as an experimental investigation but transitioned to a data analysis project due to hardware failure. Using previously acquired experimental data, we compare the meas